Abstract

The search for an electric dipole moment of the neutron tests physics beyond the Standard Model such as new sources of CP‐violation and Supersymmetry. The nEDM experiment aims to improve the sensitivity on the current limit of the electric dipole moment of the neutron to
The experiment will use a flux of Ultra Cold Neutrons (UCNs) produced and stored in a bath of superfluid He‐II. A change in precession frequency is expected for a non‐zero EDM when an electric field is applied parallel and antiparallel to a magnetic field across the neutron storage cell. A dominant parameter in terms of reducing the statistical uncertainty of this measurement is the strength of the applied electric field. An experiment to measure if superfluid He‐II can sustain up to 50 kV/cm for a volume and electrode spacings comparable to the nEDM experiment has been constructed at Los Alamos National Laboratory. It consists in a large‐area parallel plate capacitor immersed in a 200 liter central volume inside a suitable cryostat that in turn is connected to a dilution refrigerator unit. A description of test runs and the status of the experiment is presented.